Electronic apparatus and wireless communication terminal

ABSTRACT

In an electronic apparatus which is equipped with a first transmission unit for performing a first communication by an electromagnetic wave; a second transmission unit for performing a second communication by an electromagnetic wave; and a reception unit for receiving a signal transmitted from the second transmission unit, the electronic apparatus is comprised of an antenna arranged by a radiator having a size which is smaller than 1/(2π) of a wavelength of a use electromagnetic wave, which is connected to at least the second transmission unit and the reception unit.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a 371 National Stage Application of InternationalApplication No. PCT/JP20051012728, filed Jul. 5, 2005. This applicationclaims the benefit of Japanese Application No.2004-199421, filed Jul. 6,2004 and Japanese Application No.2004-367203, filed Dec. 20, 2004. Thedisclosure(s) of the above applications are incorporated herein byreference.

FIELD OF THE INVENTION

The present invention is related to an electronic apparatus and awireless communication terminal, which contain elements such as displayelements and imaging elements of portable telephones and the like, andalso are equipped with communication functions, while these elementsrequire high-speed data transmissions.

BACKGROUND ART

Very recently, while functions owned by portable telephones, notebooktype computers, digital cameras, and the like are conspicuouslyimproved, high resolution and high precision are strongly required fordisplay elements and imaging elements which are built in theseelectronic appliances, so that the structures of these electronicappliances become more complex. In particular, portable telephones arestrongly required to be made compact and in light weight as well as inlow cost, and also required to be operable in low consumption, whilecamera functions are required to be built in these portable telephonesand sizes of display units of the portable telephones are required to beincreased. As to housing structures of these portable telephones, foldedtype housings called as “clam shell type housings” and “flip typehousings” have been mainly employed.

Currently, in electronic apparatus containing these display memberelements and imaging elements, strong demands are considerably made tomanufacture large-sized display units with high resolution, and further,to make these electronic appliance compact and in light weight. Inresponse to these demands, there are many possibilities that elementmounting boards of these electronic appliances are divided into pluralsub-boards. In this case, there are many opportunities that electroniccircuits are separated to a display member side and a control side.Under such a circumstance, lengths of wiring lines for connecting CPUsto either display elements or imaging elements are necessarilyincreased. Since resolution of display elements is increased,frequencies of signals transmitted through these line paths areincreased, so that electrical connections between these electronicelements gradually become difficult.

More specifically, in clam shell type structure, CPUs are connected toeither display elements or imaging elements via narrow hinge portions.Since the resolution as to these display elements and imaging elementsis increased, amounts of data transmitted/received between both boardsare also increased, so that high-speed data transfer techniques arerequired. To solve this problem, as high-speed data transfer systems,for instance, such a technical idea that LVDS (Low Voltage DifferentialSignaling) is used to connect either a display member or an imagingelement has been proposed (Japanese Patent No. 3086456 (column 44), andJapanese Patent No. 3330359 (column 46)). Moreover, Japanese Patent No.3349426 and Japanese Patent No. 3349490 have proposed the new methods,since the above-described LVDS technical idea cannot sufficiently solvethe problem.

On the other hand, while great progress appears in semiconductormanufacturing techniques, there are such trends that integration degreesare considerably increased as a system-on-chip, and thus, all ofsemiconductor circuits which are storable within a single chip aremounted on this single semiconductor chip. As a result, a total numberof pins used to connect semiconductor chips to external circuits areconsiderably increased, and occasionally exceeds several hundreds ofconnection pins. On the other hand, while operating frequencies ofsemiconductor circuits are similarly increased, the conventionalconnecting method for connecting the semiconductor circuit to theexternal unit via the wire bonding may cause a problem as to highfrequency characteristics, and also may cause another problem thatsignals can be hardly transmitted/received between the semiconductorcircuit and the external unit. With respect to such a problem, severalresearching reports have been made in which semiconductor chips aremutually connected by way of wireless manners, or circuit blocks aremutually connected by way of wireless methods in Japanese magazine“NIKKEI MICRODEVICE” issued in Dec. 2003, page 161; JP-A-10-256478;JP-A-2000-124406; JP-A-2000-68904; and JP-A-2003-101320.

However, as to recent large screen sizes of display members, even whenthese technical ideas are executed, sufficiently satisfiable performancecould not be obtained. In other words, in small-signal serial transferoperations such as LVDS, very delicate designs as well as adjustmentsare required in order to achieve sufficiently satisfiable noise withstanding characteristics (interference with standing characteristics andcharacteristics capable of avoiding applications of interference). Inthe LVDS technique, since amplitudes of signals are small, digital ICsnecessarily handle analog signals. As a result, there is a problem thatpower consumption is increased. Also, in order to transmit signals inhigh precision, well-matched impedance terminations are required in theLVDS technique. However, there are a large number of signal lines whichrequire the impedance terminations, and transfer impedances are low,e.g., 100 ohms. Accordingly, there is another problem that electricpower consumed in these terminating resistances becomes not allowablevalues, namely becomes high.

Furthermore, in such a case that wiring lines pass through movableportions such as hinge portions, since characteristic impedances arechanged due to bending degrees of these movable portions, an impedancemismatching phenomenon may occur in response to conditions, and thus,signal deteriorations may be induced because of reflections at thebending portions. As a consequence, there are other problems that speedsof data to be transferred are restricted, and/or limitations are made asto mounting methods and arrangements of components.

In addition, as apparent from the foregoing descriptions, since a totalnumber of signals transmitted/received via the hinge portions amounts toseveral tens of signal lines, and wiring lines formed on boards cannotbe used, flexible boards are connected to each other via connectors.There is such a drawback that the use of such a flexible board and theconnection by such a connector cause high cost, and further, connectionreliability is low.

Furthermore, increasing of wiring lines required for transferring datain high speeds requires physical spaces used for these wiring lines.Apparently, a large limitation is made of designs for electronicappliances.

In addition, when such large amounts of data are transferred in highspeeds by using long wiring lines, if electromagnetic fields radiatedfrom signal lines are increased, then this may cause electromagneticinterferences which are given to other electronic appliances, or the ownelectronic appliances. While amplitude levels at signal receptionterminals have been defined in rules in signal transfer operation by theconventional signal lines, even if sufficiently high qualities aresecured at the signal reception terminals, the amplitude levels of thesignals cannot be lowered. In other words, EMI measures cannot besatisfactorily taken, so that this may cause designs of electronicappliances to be restricted, and may cause cost of these electronicappliances to be increased. Also, since electronic circuits on thetransmission side are driven, loads on the signal reception terminalsand stray capacitances of line lines are driven at the same time, sothat extra energy is necessarily required so as to transfer signals.That is to say, this may increase power consumption.

These problems may be entirely solved if the conventional wirelesscommunication techniques are conducted to communications executed amongthe respective blocks of electronic circuits and integrated circuits,and data transfer operations in such portions where wiring lines cannotbe formed are carried out by employing wireless data transfer techniquesby electromagnetic waves. In connection with the above-describedconventional wireless communication technique, an attention is paid tothe technical ideas which have been disclosed in Japanese magazine“NIKKEI MICRODEVICE” issued in Dec. 2003, page 161; JP-A-10-256478;JP-A-2000-124406; JP-A-2000-68904; and JP-A-2003-101320.

However, in order to conduct the conventional wireless technical ideasto data transfer operations within electronic appliances, mechanismsthereof are very complex and actual installations thereof can be hardlycarried out, as compared with those of such a case that data have beentransferred by way of conductor lines. In particular, in portabletelephone terminals, power of transmitters of telephone functions(namely, principle object of portable telephone terminals) is extremelyhigh, and thus, the transmission signals may give large disturbances towireless connections established within the same electronic appliance(portable telephone terminal). As apparent from the foregoingexplanations, as to the wireless communication executed in the sameelectronic appliance, only electromagnetic waves having low levels maybe limitedly used which do not cause restriction subjects restricted bythe Japanese electromagnetic wave control law, and the like. In fact, adifference between these signal levels is reached to 80 dB. Conversely,there are some possibilities that signals used to connect internalappliances may be mixed into telephone receivers as noise and may givedisturbances thereto, for example, may lower sensitivities of thesereceivers. None of these conventional techniques discloses effectivesolving means with respect to the above-described problems.

Also, an antenna used to internally connect electronic appliancesconstitutes a very difficult problem when the above-describedconventional wireless techniques are carried out. None of theabove-described Japanese patent publications 5 to 8 describes anyeffective solving measure. For instance, the Japanese patent publication6 describes that the antenna having the length equal to ¼ of thewavelength of the electromagnetic wave having the frequency of 1.5 GHzis formed on the integrated circuit. However, the wavelength of such anelectromagnetic wave having the frequency of 1.5 GHz is equal to 20 cm,and thus, it is practically difficult to form such an antenna having a¼-wavelegnth antenna length (namely, 5 cm) on the integrated circuit.Also, the Japanese patent publications 7 and 8 describe structures thatinsulating films are formed on semiconductor chips, and plane-shapedantenna radiators are positioned on the insulating films of thesemiconductor chips. However, such a fact can be easily understood byordinarily skilled engineers. That is, the electromagnetic waves cannotbe effectively radiated from the antenna radiators positioned on theinsulating films due to such thicknesses substantially equal to thethicknesses of the insulating films formed on the semiconductor chips.

Further, while communications are executed within electronic appliancesin a point-blank range, propagations of electromagnetic waves must beconsidered based upon not only a far distance range where the normalcommunication line is applied, but also a specific propagationcharacteristic in the vicinity of the antenna.

To clarify this matter, a simulation executed based upon theconventional technique will now be explained with reference to drawings.

FIG. 11 is an illustration of a portable telephone terminal equippedwith a clam shell structure, namely, a simulation of a portabletelephone terminal which is arranged by both a display body unit 701 onwhich a display apparatus is mounted, and a main body unit 702 on whicha baseband processor and an input apparatus (keyboard) are mounted.Although both the display body unit 701 and the main body unit 702 maybe folded while a line X-X′ is used as an axis, as indicated in thisdrawing, a simulation is carried out under such a condition that theseunits 701 and 702 are equipped with a clam shell structure, namely, asimulation of a portable telephone terminal which is arranged by both adisplay member unit 701 on which a display apparatus is mounted, and amain body unit 702 on which a baseband processor and an input apparatus(keyboard) are mounted. Although both the display body unit 701 and themain body unit 702 may be folded while a line X-X′ is used as an axis,as indicated in this drawing, a simulation is carried out under such acondition that these units 701 and 702 are opened, namely under thenormal condition.

In this portable telephone terminal model, in order that data to bedisplayed on the display apparatus is transmitted from the main bodyunit 702 to the display body unit 701 by employing electromagneticwaves, both a transmission-purpose antenna 703 and a reception-purposeantenna 704 are provided thereon respectively. Also, while atransmission/reception-purpose antenna 705 of a portable telephone isprovided on the display body unit 701, electric power is fed from themain body unit 702 via a coaxial cable under the normal condition. Inthis drawing, any of these antennas were handled as mono-pole antennasfor the sake of an easy simulation. In an actual embodiment mode, suchlow height antennas as an inverted-F type antenna must be selected asthe antennas 703 and 704. However, it is conceivable that there is nosuch a large difference in simulation results of two antenna cases.Also, assuming now that the portable telephone-purpose antenna 705transmits/receives electromagnetic waves in a frequency range of 2 GHzwhich is used in the third generation portable telephone system, and theinternal appliance communication-purpose antennas 703 and 704 useelectromagnetic waves in a frequency range of 5 GHz, such cylinders areemployed as radiators, the lengths of which are 37.5 mm and 15 mm andcorrespond to a ¼ wavelength, and the diameters of which are 1 mm.

FIG. 12 represents a typical S parameter of an S matrix in the case thatthe internal appliance communication-purpose transmission antenna 703 isset as a port 1, the internal appliance communication-purpose receptionantenna 704 is set as a port 2, and the telephone-purpose antenna 705 isset as a port 3.

In FIG. 12, a ratio of energy transferred from the internal appliancecommunication-purpose transmission antenna 703 to the reception antenna704 is “S₂₁,” whereas a ratio of energy transferred from the portabletelephone antenna 705 to the internal appliance communication-purposereception antenna 704 is “S₂₃.” As understood from this drawing, theratio “S₂₁” is approximately −16dB in the frequency of 5GHz used in theinternal appliance communication, and the ratio “S₂₃” is −25 dB in thefrequency of 2 GHz for the portable telephone.

In other words, a level difference between the transmission power of theinternal appliance communication-purpose transmission antenna 703 andthe transmission power of the portable telephone-purpose antenna 705 inthe internal appliance communication-purpose reception antenna 704 isdirectly reflected to a DU ratio (Desire/Undesire ratio). Transmissionpower for a portable telephone is 23 dBm in maximum, and also, maximumtransmission power which is permitted to a non-licensed radio stationbased upon Japanese electromagnetic wave control law corresponds to−64.3 dBm converted by EIRP. In accordance with the above-describedsimulation, both signals appear at the internal appliancecommunication-purpose antenna 704 as an extremely large level differenceof approximately 80 dB (23−(−64.3)−(16−25)=78.3).

In an internal appliance communication-purpose reception unit, a filtermeans for removing this unwanted signal is required. However, in anactual case, it is practically difficult to mount a filter capable ofremoving such an extremely large level difference on this receptionunit. Symbol “S₁₃” indicates a ratio of energy which is transmitted fromthe portable telephone-purpose antenna 705 to the internal appliancecommunication-purpose transmission antenna 703. since both the antennascorrespond to transmission antennas, this energy ratio “S₁₃” does notcause a problem. However, for example, in a case that image dataacquired by an imaging element mounted on the display body unit 701 istransmitted to the main body unit 702 in such a portable telephoneterminal equipped with the above-described imaging element, forinstance, in a portable telephone equipped with a camera, the internalappliance communication-purpose antenna 703 is used as areception-purpose antenna, and thus, a value of this energy ratio “S₁₃”may be employed for a reference purpose. It should also be noted thatsince the S matrix corresponds to a symmetrical matrix, S₃₁=S₁₃. In thiscase, a condition becomes more severe, and thus, the DU ratio is reachedto −90 dB.

As a consequence, the present invention has been made to solve theabove-described various sorts of problems occurred when a large amountof data are transferred in high speeds and in the wireless mannerbetween the respective circuit blocks employed in the conventionalelectronic appliances, and in particular, to solve the problems as tothe disturbance eliminations and the sizes of the antennas in a casethat the strong electromagnetic wave oscillating source is present whichconstitutes the principle purpose owned by the electronic appliancewithin the own electronic appliance, and therefore, has an object toprovide both an electronic apparatus and a wireless communicationterminal, which are capable of removing the drawbacks and therestrictions of the conventional data transfer system, and can bemanufactured in low cost and with high reliability.

DISCLOSURE OF THE INVENTION

To solve the above-described problems, an electronic apparatus,according to the present invention, is featured by such an electronicapparatus equipped with at least a first transmission unit forperforming a first communication by an electromagnetic wave; a secondtransmission unit for performing a second communication by anelectromagnetic wave; and a reception unit for receiving a signaltransmitted from the second transmission unit; in which the electronicapparatus is comprised of: an antenna in which a diameter of a sphereincluding a radiator is smaller than 1/(2π) of a wavelength of anelectromagnetic wave used in either the second transmission unit or thereception unit.

In accordance with the above-described arrangement, the signaltransmitted from the second transmission unit is received by thereception unit within the same electronic appliance. If thesetransmission and reception units are used so as to transfer a largeamount of data in a high speed within the electronic appliance, sincethe data transfer operation is carried out by way of the electromagneticwaves while an air space is used as a medium, the various sorts ofconventional problems caused by the high-speed and large-amount datatransfer operation can be solved. In addition, since such antennascalled as “small antennas” are employed as the antennas used in thesetransmission and reception units, the frequency bands thereof are narrowbands, and these small antennas represent strong frequency selectivecharacteristics. As a result, the disturbances of the transmissionsignal transmitted from the first transmission unit can be reduced.Also, since the antennas are made compact, a so-called “proximity area”thereof is narrow. As a consequence, even when these compact antennasare arranged at narrow places such as spaces within the same appliance,signal lines can be designed in an easy manner.

Also, an electronic apparatus, according to the present invention, isfeatured by that the antenna is constituted by the radiator; and areactance element for canceling a reactance component of the radiator.

In accordance with the above-described arrangement, since the reactanceelement capable of canceling the reactance component owned by theantenna is provided, the antenna can be manufactured in highperformance, and the superior radiation efficiency can be obtained.

Also, an electronic apparatus, according to the present invention, isfeatured by that the first transmission unit, the second transmissionunit, or either a partial circuit or all circuits of the reception unitare constructed on a semiconductor integrated circuit; and either aportion or all of reactance components of the radiator of the antennaare canceled by both a reactance component owned by a wiring line on thesemiconductor integrated circuit, and a reactance component owned by awiring line defined from the semiconductor integrated circuit up to theradiator of the antenna.

In accordance with the above-described arrangement, both thetransmission unit and the reception unit used to transmit/receive thesignals within the electronic appliance are simultaneously formed on theintegrated circuit which constitutes the electronic appliance, so thatthe electronic appliance can be made compact and in low cost, andfurther, can be manufactured in high reliability. Also, since a portionof the reactance component owned by the antenna can be compensated bythe stray element owned by such a wiring line defined from thesemiconductor integrated circuit up to the antenna, the electronicapparatus can eliminate the adverse influence caused by the strayelement such as the inductance of the bonding wire of the semiconductorintegrated circuit, which constitutes the conventional problem.

Also, an electronic apparatus, according to the present invention, isfeatured by such an electronic apparatus equipped with at least a firsttransmission unit for performing a first communication by anelectromagnetic wave; a second transmission unit for performing a secondcommunication by an electromagnetic wave; and a reception unit forreceiving a signal transmitted from the second transmission unit; inwhich the electronic apparatus is comprised of: an antenna in which adiameter of a sphere including a radiator is smaller than 1/(2π) of awavelength of an electromagnetic wave used in either the secondtransmission unit or said reception unit; evaluation means forevaluating a reception condition of the reception unit; control meansfor controlling a frequency of an electromagnetic wave transmitted bythe second transmission unit; and feedback means for feeding back anevaluation result made by the evaluation means to the control means.

In accordance with the above-explained arrangement of the presentinvention, the signal transmitted from the second transmission unit isreceived by the reception unit within the same electronic appliance. Ifthese transmission and reception units are used so as to transfer alarge amount of data in a high speed within the electronic appliance,since the data transfer operation is carried out by way of theelectromagnetic waves while an air space is used as a medium, thevarious sorts of conventional problems caused by the high-speed andlarge-amount data transfer operation can be solved. In addition, sincesuch antennas called as “small antennas” are employed as the antennasused in these transmission and reception units, the frequency bandsthereof are narrow bands, and these small antennas represent strongfrequency selective characteristics. As a result, the disturbances ofthe transmission signal transmitted from the first transmission unit canbe reduced. Also, since the antennas are made compact, a so-called“proximity area” thereof is narrow. As a consequence, even when thesecompact antennas are arranged at narrow places such as spaces within thesame appliance, signal lines can be designed in an easy manner. Sincesuch a compact type antenna owns the strong frequency selectivecharacteristic, this compact type antenna has a high sensitivity withrespect to a fluctuation of circuit manufacturing operations and avariation of peripheral conditions. However, since the electronicapparatus of the present invention is equipped with the feedback meansand can be controlled to be continuously operated at an optimumfrequency, the unstable elements caused by this factor can be removed.

Also, an electronic apparatus, according to the present invention, isfeatured by that a shape of the radiator of the antenna is a line shape.

In accordance with the above-described arrangement of the presentinvention, while the antenna can be designed in an easy manner, thefrequency characteristic of the antenna can be made in the narrowfrequency band, and thus, can own the strong frequency selectivecharacteristic.

Also, an electronic apparatus, according to the present invention, isfeatured by that the radiator of the antenna is constituted by a printpattern formed on a printed circuit board.

In accordance with the above-described arrangement of the presentinvention, the antenna can be formed on the integrated circuit incombination with the wiring pattern, and the mounting step of theantenna can be simplified. In addition, a communication appliance can bemade compact and in low cost, while reliability of this communicationappliance can be improved.

Also, a wireless communication terminal, according to the presentinvention, is featured by such a wireless communication terminalcomprising: a first housing unit; a second housing unit; a coupling unitfor coupling the first housing unit to the second housing unit in such amanner that a positional relationship between the first housing unit andthe second housing unit is changeable; an external wirelesscommunication-purpose antenna which is mounted on either the firsthousing unit or the second housing unit; an external wirelesscommunication control unit mounted on the first housing unit, for mainlycontrolling an external wireless communication performed via theexternal wireless communication-purpose antenna; a display unit mountedon the second housing unit; a first internal wireless communicationcontrol unit mounted on the first housing unit, for controlling aninternal wireless communication executed between the first housing unitand the second housing unit; a second internal wireless communicationcontrol unit mounted on the second housing unit, for controlling aninternal wireless communication executed between the first housing unitand the second housing unit; a first internal wirelesscommunication-purpose antenna mounted on the first housing unit, inwhich a diameter of a sphere including a radiator is smaller than 1/(2π)of a wavelength of an electromagnetic wave used in the internal wirelesscommunication; a second internal wireless communication-purpose antennamounted on the second housing unit, in which the diameter of the sphereincluding the radiator is smaller than 1/(2π) of the wavelength of theelectromagnetic wave used in the internal wireless communication; and aninternal wireless timing control unit for controlling transmissiontiming of the electromagnetic wave transmitted in the internal wirelesscommunication based upon transmission timing of the electromagnetic wavetransmitted via the external wireless communication-purpose antenna.

In accordance with the above-explained arrangement of the presentinvention, the frequency range of the internal wirelesscommunication-purpose antenna can be made narrow, and the frequencyselective characteristic can be improved, and further, the directivitythereof can be relaxed. As a consequence, the interference between theexternal wireless communication and the internal wireless communicationcan be reduced and the disturbance can be lowered. Even in a case that aclam shell structure is employed in a portable telephone, data transferoperation between the housings of the portable telephone can be carriedout in a wireless mode under stable condition. As a result, even in thecase that an amount of data transmitted/received between the housings isincreased in correspondence with high resolution of the display unitmounted on the portable telephone, while a complex structure of acoupling unit can be suppressed, the cumbersome mounting steps can beavoided. As a result, the portable telephone can be made compact andslim in higher reliability, while the cost-up aspect is suppressed; andfurther, while the portability of the portable telephone is notdeteriorated, the portable telephone can be manufactured with a largedisplay screen and can be equipped with multiple functions.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view for representing a condition that a clamshell type portable telephone of the present invention is opened onwhich an antenna is mounted.

FIG. 2 is a perspective view for representing a condition that the clamshell type portable telephone of the present invention is closed onwhich the antenna is mounted.

FIG. 3 is a perspective view for showing an outer appearance of a rotarytype portable telephone of the present invention, on which an antenna ismounted.

FIG. 4 is a diagram for explaining an embodiment of the presentinvention.

FIG. 5 is a diagram for explaining an antenna portion in detail in theembodiment of the present invention.

FIG. 6 is a diagram for describing an effect of the antenna portion inthe embodiment of the present invention.

FIG. 7 is a diagram for indicating a field radiated from a very smallcurrent element.

FIG. 8 is a block diagram for describing an embodiment of the presentinvention.

FIG. 9 is a diagram for explaining another embodiment of the presentinvention.

FIG. 10 is a diagram for explaining a further embodiment of the presentinvention.

FIG. 11 is a diagram for describing the conventional technique.

FIG. 12 is a diagram for describing the conventional technique.

BEST MODE FOR CARRYING OUT THE INVENTION

Referring now to drawings, embodiment modes of the present inventionwill be described.

FIG. 1 is a perspective view for representing a condition that a clamshell type portable telephone of the present invention is opened onwhich an antenna is mounted. FIG. 2 is a perspective view forrepresenting a condition that the clam shell type portable telephone ofthe present invention is closed on which the antenna is mounted.

In FIG. 1 and FIG. 2, an operation button 4 has been arranged on asurface of a first housing unit 1, and also, a microphone 5 has beenprovided on a lower edge of the first housing unit 1. Also, a displaymember 8 has been provided on a surface of a second housing unit 2, aspeaker 9 has been provided on an upper edge of the second housing unit2, and an external wireless communication-purpose antenna 6 has beenmounted on an upper edge of the second housing unit 2. In this case,signals which are transmitted/received by the external wirelesscommunication antenna 6 can be communicated via a coaxial cable with thefirst housing unit 1. Also, the external wireless communication-purposeantenna 6 may be alternatively mounted on the first housing unit 1 asindicated by reference numeral 6.

Also, both a display member 11 and an imaging element 12 have beenprovided on an outer plane of the second housing unit 2. It should alsobe noted that as the display members 8 and 11, for example, a liquidcrystal display panel, an organic EL panel, or a plasma display panelmay be employed. Also, as the imaging element 12, either a CCD or a CMOSsensor maybe employed. Also, internal wireless communication-purposeantennas 7 and 10 which perform an internal wireless communicationbetween the first housing unit 1 and the second housing unit 2 have beenprovided in both the first housing unit 1 and the second housing unit 2,respectively.

Then, the first housing unit 1 is coupled via a hinge 3 to the secondhousing unit 2. Since the second housing unit 2 is rotated by settingthe hinge 3 as a fulcrum, the second housing unit 2 can be folded on thefirst housing unit 1. Then, since the second housing unit 2 is closed onthe first housing unit 1, the operation button 4 can be protected by wayof the second housing unit 2, and it is possible to avoid that theoperation button 4 is mistakenly operated when the portable telephone iscarried. Also, since the second housing unit 2 is opened from the firsthousing unit 1, the operation button 4 can be operated while the displaymember 8 is viewed; a telephone communication can be carried out whilethe speaker 9 and the microphone 5 are used; and also, an imagingoperation can be carried out while the operation button 4 is operated.

In this case, since the clam shell structure is employed, the displaymember 8 can be arranged over a substantially entire area of the secondhousing unit 2, and the size of the display member 8 can be enlargedwithout deteriorating the portability of the portable telephone, so thatthe visible characteristic can be improved.

Also, since the internal wireless communication-purpose antennas 7 and10 are provided in the first housing unit 1 and the second housing unit2 respectively, data transmission operations can be carried out betweenthe first housing unit 1 and the second housing unit 2 by way ofinternal communications by using the internal wirelesscommunication-purpose antennas 7 and 10. For example, both image dataand voice data which have been acquired into the first housing unit 1via the external wireless communication-purpose antenna 6 aretransmitted to the second housing unit 2 by way of the internal wirelesscommunication by using the internal wireless communication-purposeantennas 7 and 10, so that an image may be displayed on the displaymember 8 and voice may be outputted from the speaker 9. Also, imagingdata acquired by the imaging element 12 is transmitted from the secondhousing unit 2 to the first housing unit 1 by way of the internalwireless communication by employing the internal wirelesscommunication-purpose antennas 7 and 10, and then, may be sent out to anexternal unit via the external wireless communication-purpose antenna 6.

As a result, there is no need for transmitting the data between thefirst housing unit 1 and the second housing unit 2 by way of a wiremanner, but also, a flexible wiring board equipped with multiple pins isno longer penetrated through the hinge 3. Accordingly, the complexstructure of the hinge 3 can be suppressed; the cumbersome mountingsteps can be avoided, the portable telephone can be made compact andslim in higher reliability, while the cost-up aspect is suppressed; andfurther, while the portability of the portable telephone is notdeteriorated, the portable telephone can be manufactured with a largedisplay screen and can be equipped with multiple functions.

FIG. 3 is a perspective view for showing an outer appearance of a rotarytype portable telephone of the present invention, on which an antenna ismounted.

In FIG. 3, an operation button 24 has been arranged on a surface of afirst housing unit 21, and also, a microphone 25 has been provided on alower edge of the first housing unit 21. Also, a display member 28 hasbeen provided on a surface of a second housing unit 22, a speaker 29 hasbeen provided on an upper edge of the second housing unit 22, and anexternal wireless communication-purpose antenna 26 has been mounted onan upper edge of the second housing unit 22. In this case, signals whichare transmitted/received by the external wireless communication antenna26 can be communicated via a coaxial cable with the first housing unit21. Also, the external wireless communication-purpose antenna 26 may bealternatively mounted on the first housing unit 21 as indicated byreference numeral 26′.

Also, internal wireless communication-purpose antennas 27 and 30 whichperform an internal wireless communication between the first housingunit 21 and the second housing unit 22 have been provided in both thefirst housing unit 21 and the second housing unit 2, respectively.

Then, the first housing unit 21 is coupled via a hinge 23 to the secondhousing unit 22. Since the second housing unit 22 is horizontallyrotated by setting the hinge 23 as a fulcrum, the second housing unit 22can be folded on the first housing unit 21. Also, the second housingunit 22 can be shifted from the first housing unit 21. Then, since thesecond housing unit 22 is arranged in such a manner that this secondhousing unit 22 is overlapped on the first housing unit 21, theoperation button 24 can be protected by way of the second housing unit22, and it is possible to avoid that the operation button 24 ismistakenly operated when the portable telephone is carried. Also, sincethe second housing unit 22 is horizontally rotated so as to be shiftedfrom the first housing unit 21, the operation button 24 can be operatedwhile the display member 28 is viewed; and a telephone communication canbe carried out while the speaker 29 and the microphone 25 are used.

In this case, since the internal wireless communication-purpose antennas27 and 30 are provided in the first housing unit 21 and the secondhousing unit 22 respectively, data transmission operations can becarried out between the first housing unit 21 and the second housingunit 22 by way of internal communications by using the internal wirelesscommunication-purpose antennas 27 and 30. For example, both image dataand voice data which have been acquired into the first housing unit 21via the external wireless communication-purpose antenna 26 (or 26′) aretransmitted to the second housing unit 22 by way of the internalwireless communication by using the internal wirelesscommunication-purpose antennas 27 and 30, so that an image may bedisplayed on the display member 28 and voice may be outputted from thespeaker 29.

As a result, a flexible wiringboard equipped with multiple pins is nolonger penetrated through the hinge 23. Accordingly, the complexstructure of the hinge 23 can be suppressed; the cumbersome mountingsteps can be avoided, the portable telephone can be made compact andslim in higher reliability, while the cost-up aspect is suppressed; andfurther, while the portability of the portable telephone is notdeteriorated, the portable telephone can be manufactured with a largedisplay screen and can be equipped with multiple functions.

It should also be understood that although the portable telephones havebeen exemplified in the above-described embodiment mode, the presentinvention may be alternatively applied to video cameras, PDAs (PersonalDigital Assistants), notebook type personal computers, and the like.

Embodiment 1

FIG. 4(A) is a perspective diagram for showing an embodiment accordingto the present invention, and FIG. 4(B) is a sectional view of theembodiment of FIG. 4(A), cut away on a plane which involves a straightline indicated by an arrow “X-Y” in FIG. 4(A).

In FIG. 4, reference numeral 101 shows a display body unit on which aliquid crystal display member and an imaging element are mounted, andthe display member is mounted on a dielectric board 107 in combinationwith a display member drive circuit, and the like. Reference numeral 102shows a main body unit; and an input apparatus such as a keyboard, a CPUof the main body unit 102, a modulating/demodulating circuit required ina telephone function process operation, and the like are mounted on adielectric board 108. Display data produced in the main body unit 102 isprocessed by a modulating circuit and the like mounted on the main bodyunit 102, and thereafter, the processed display data is radiated aselectromagnetic waves from an internal appliance communication-purposetransmission antenna 103, and then, the transmitted display data isreceived by an internal appliance communication-purpose receptionantenna 104. The received signal is processed by a reception circuitprovided on the display body unit 101 based upon demodulating processoperation, and then, is converted into display data, so that the contentof the display data is displayed on the display member provided on thedisplay body unit 101. Reference numeral 105 shows an antenna used for aportable telephone. Electric power is supplied to the antenna 105 via acoaxial cable by the main body unit 102.

A positional relationship of the antenna of FIG. 4 and a used frequencythereof are identical to those of the prior art shown in FIG. 11. Also,rear planes of the dielectric boards 107 and 108 of both the displaybody unit 101 and the main body unit 102 have been covered by aconductor 106 as a ground plane. In FIG. 4(B), the same referencenumerals 106 are indicated at two positions. This is because the samereference numerals 106 represent the same components which aremaintained at the equi-potential via the hinge portion. Also, althoughthe ground plane covers the substantially entire plane of the rearplanes of the dielectric boards, this illustration is made in order toeasily perform a simulation. In an actual case, this ground plane isused as the ground of a circuit to be mounted, and thus, this groundplane becomes a complex pattern.

FIG. 5 is a diagram for explaining the internal appliancecommunication-purpose transmission/reception antennas 103 and 104 inmore detail, related to the present invention. It should be understoodthat the same reference numerals shown in FIG. 4 are employed as thosefor denoting the same structural elements of FIG. 5. In this embodiment,as to both the transmission/reception antennas 103 and 104, arectangular-shaped conductor having a length of 6.5 mm and a width of 1mm is employed as an antenna radiator. This rectangular-shaped conductormay be constituted in the form of a conductor pattern of a printedcircuit board, functioning as a portion of a circuit board, and owns amerit in manufacturing process, since such a specific construction and aspecific element as an inverted-F type antenna are not required. A sizeof this antenna is nearly equal to 1/10 of the wavelength (6 cm) of theuse frequency (5 GHz), and is shorter than, or equal to 1/(2 π) of thewavelength, and thus, is called as a “small antenna”. It should also benoted that symbol “π” is a ratio of the circumference of a circle to itsdiameter.

In order to increase radiation efficiencies of both the antennas, therear surfaces of the radiators are escaped from the ground plane. As tothe internal appliance communication-purpose transmission antenna 103, arectangular hole 109 having a dimension of 7×9.5 mm has been pierced inthe rear surface ground plane. Also, the internal appliancecommunication-purpose antenna 104 is constituted on an edge plane of theboard, and a notch portion has been formed on the ground plane. Itshould also be noted that these antennas and components are merelyexemplified as one example, and therefore, may be freely changed for thesake of easy component arrangements. While points indicated by symbols“X” in FIG. 5 are employed as feeding points, electric power is fedbetween the internal appliance communication transmission/receptionantennas 103 and 104 and points on the ground planes located just underthese antennas 103 and 104.

FIG. 6 indicates calculation results by executing a simulation of an Sparameter when the internal appliance communication-purpose transmissionantenna 103 is used as a port 1, the internal appliancecommunication-purpose reception antenna 104 is used as a port 2, and theportable telephone-purpose antenna is used as a port 3. As apparent fromthis calculation result of FIG. 6, a ratio “S₂₁” of energy transferredfrom the internal appliance communication-purpose transmission antenna103 to the reception antenna 104 is −16 dB in the use frequency 5 GHz,whereas a ratio “S₂₃” of energy transferred from the portable telephoneantenna 105 to the internal appliance communication-purpose receptionantenna 104 is −49 dB in the use frequency 2 GHz. In other words, adifference between the energy ratios S₂₁ and S₂₃ is reflected to thelevel difference between the transmission power of the internalappliance communication-purpose transmission antenna 103 and thetransmission power of the portable telephone-purpose antenna 105 in theinternal appliance communication-purpose reception antenna 104, and a DUratio may be improved by 33 dB. In order to perform an internalappliance communication without any problem, the DU ratio must befurther improved by 47 dB. However, such an interference may besufficiently prevented by a diffusion gain and the like obtained by afilter and a communication system. This may cause a system design tobecome easy, and also, may cause system performance to be considerablyimproved.

Generally speaking, an antenna having a size that this antenna can bestored into a sphere whose diameter is equal to 1/(2π) of a wavelengthis referred to as a “small antenna.” Within a distance measured from aradiation source of electromagnetic waves, which is shorter than, orequal to 1/(2π) of a wavelength, an electrostatic field and an inductivefield are superior to a radiative field, and are referred to as areactive radiation area. One terminal of a small antenna is contained inthe reactive radiation area, as viewed from the other terminal of thissmall antenna. Also, a phase difference from a center of an antenna upto a terminal thereof becomes smaller than, or equal to 0.5 radian, andthis is an area that a difference between a circular measure “x” and sinx becomes smaller than, or equal to 2%, and also corresponds to an areathat sin x can be approximated by “x.” In a system using such a smallantenna, there is substantially no a radiation proximity area which iscalled as a Fresnel area, and a communication line can be easilydesigned. When the antenna becomes such a small antenna, a radiationimpedance becomes reactive, and a real part of a radiation impedance islowered. This implies that “Q” of the radiation impedance is increasedand a band is narrowed. Also, radiation directivity becomes gentle, anda gain along the maximum radiation direction is approximated to 1.5.

FIG. 7 is a diagram for indicating a field which is radiated from a verysmall current element.

In FIG. 7, a radiation electromagnetic field radiated from a very smallcurrent element is conceived as a summation of three components whichare directly proportional to 1/r, 1/r², and 1/r³ with respect to adistance “r” from a wave source, which are called as a radiative field,an inductive field, and an electrostatic field. When the distance “r”becomes 1/K (symbol “K” indicates 2π/λ), “Kr” becomes equal to 1, andthus, dimensions of the respective fields are made coincident with eachother. When the distance “r” is smaller than 1/K, the strengths of boththe inductive field and the electrostatic field become dominant, ascompared with the radiative field. This area corresponds to a reactiveradiation area.

In such a case that a radiator of an antenna is completely included bythe reactive radiation area, namely, in the case that a diameter of asphere which includes the radiator is smaller than 1/K, i.e., smallerthan 1/(2π), a reactance component of this antenna becomes dominant, sothat both a frequency range of this antenna and an antenna efficiencythereof are largely influenced. This phenomenon has been described indetail in, for instance, the below-mentioned publication:

Chu, L. I. “Physical Limitations of omni-directional Antennas”, Journalof Applied Physics, 1948, 19, pp. 1163-1175.

McLean, J. S. “A Re-examinations of the Fundamental Limits on theRadiation Q of Electrically Small Antennas” IEEE trans. AntennasPropagation Vol 44, pp 672-676. 1996.

The embodiments of the present invention utilize this characteristic ofthe small antenna, and can effectively utilize a reactance componentowned by the antenna by setting a size of the antenna in such a mannerthat the diameter of the sphere including the radiator of the antennabecomes smaller than 1/(2π) of a wavelength of a use electromagneticwave, and also can eliminate interference by sharpening a frequencyselecting characteristic owned the antenna itself. Also, in the smallantenna, since directivity of this small antenna is relaxed, even insuch a positional relationship between a transmission side and areception side in a complex housing structure having a so-called“two-axial construction”, the S₂₁ characteristic becomes flat and stableoperations can be realized. As to this complex housing structure, in aportable telephone having a clam shell structure, housings may berotated, while the straight line indicated by “Z” of FIG. 4(A) isemployed as an axis.

In this embodiment 1, a simulation is carried out based upon such a sizethat a diameter can be stored in a sphere of 1/(3π) of a wavelength, andthen, this embodiment 1 represents that a superior characteristic can beobtained. Furthermore, such a size may be alternatively employed inwhich a diameter may be stored in a sphere of ⅕π, of a wavelength. Inthis alternative case, it is suitable to arrange an antenna on a chip,or within a package, or on the package. It is preferable that a lowerlimitation as to a size of an antenna is selected to be larger than, orequal to a line width of a wiring line.

FIG. 8 is a block diagram for indicating a major portion of anelectronic circuit of an apparatus according to an embodiment of thepresent invention.

In FIG. 8, a CPU 401 produces display data which should be displayedbased upon information acquired from a portable telephone circuit 406and a calculation, and then records the display data in a video memory402. A liquid crystal controller 403 reads display data 419 which isdisplayed on the display member from the video memory 402 in apredetermined sequence, and then, outputs the read display data 419 incombination with a vertical synchronization signal 421, and a horizontalsynchronization signal 420. The display data 419 isparallel-to-serial-converted by a parallel/serial converting circuit404, and then, transmits the parallel/serial-converted display data 419to a logic circuit 407. A synchronizing circuit 405 produces a preambleby receiving the horizontal synchronization signal 420 and the verticalsynchronization signal 421. This preamble is employed so as to establisha synchronization which is required for communication, for example,timing for a synchronous detection. The logic circuit 407 receives thesignal derived from the parallel/serial converting circuit 404 and thesignal derived from the synchronizing circuit 405 SO as to produce apacket (data) used in a wireless communication, and this packet data ismodulated by a modulator 408 based upon a carrier frequency produced bya carrier wave oscillator 409, and then, the modulated packet data istransmitted by a transmission antenna 410. This transmission antenna 410corresponds to the internal appliance communication-purpose transmissionantenna 103 shown in FIG. 4. The above-described circuit elements aremounted on the display body unit 101 of FIG. 4. A portabletelephone-purpose antenna 427 is mounted on the display member unit (101shown in FIG. 1), and is connected to the portable telephone circuit 406provided in the main body unit 102 by using a coaxial cable.

A reception antenna 411 receives the electromagnetic wave signaltransmitted from the transmission antenna 410. The reception antenna 411corresponds to the internal appliance communication-purpose receptionantenna 104 shown in FIG. 4. After this signal has been amplified by apreamplifier 412, interference waves in an unnecessary frequency bandare eliminated from this amplified signal by a bandpass filter 413, andthen, the filtered signal is entered to another synchronizing circuit414. The bandpass filter 413 may be replaced by such a notch filtercapable of blocking a specific frequency band, for instance, atelephone-purpose transmitter frequency band. Alternatively, thebandpass filter 413 may be provided at a prestage of the preamplifier412. In the case that the bandpass filter 413 is provided at theprestage of the preamplifier 412, since the interference waves areremoved before the signal is inputted to the preamplifier 412, a marginmay be produced in the dynamic range of the preamplifier 412. To thecontrary, if the bandpass filter 413 owns a loss, then the noise figureof the preamplifier 412 is deteriorated.

Even in anyone of these cases, since the frequency selectingcharacteristic is realized by the transmission antenna 410 and thereception antenna 411, a margin may be produced in a design, so that asystem structure may be easily made. The synchronizing circuit 414detects the preamble contained in the reception signal packet, andproduces both synchronization timing and a clock which are required fora demodulating operation in conjunction with a PLL 415. In response to areception signal, a demodulating circuit 416 demodulates the receptionsignal packet by using the outputs of the synchronizing circuit 414 andthe PLL 415. Another logic circuit 418 produces a horizontalsynchronization signal 423, a vertical synchronization signal 424, and atransfer clock 425 of an X driver from the demodulated packet by beingfitted to the timing with respect to display data 422 contained in thepacket. Then, the logic circuit 418 outputs the horizontalsynchronization signal 423, the vertical synchronization signal 424, andthe transfer clock 425 to a liquid crystal driver employed in a liquidcrystal display member LCD 426 respectively so as to perform a displayoperation. The above-explained circuit elements are mounted on the mainbody unit 102 of FIG. 4.

As to the oscillation frequency of the carrier wave oscillator 409, afrequency is selected which does not give interference to originalobjects of electronic appliances utilizing electromagnetic waves such asa radio receiver and a portable telephone, and also which is notadversely influenced by these electronic appliances. As explained inthis embodiment 1, if the use frequency of approximately 5 GHz isselected, then the occupied range is approximately 200 MHz even whendata of 100 Mbps is transmitted. Therefore, normally, the portabletelephone of this embodiment 1 may be used without any problem in themost opportunity. Apparent from FIG. 6, a −3 dB band of the energy ratio“S₂₁” corresponds to 400 MHz. Thus, even if a narrow band is realized byemploying such a small antenna, then there is a sufficient margin in thefrequency band.

Since the above-described structure is employed, the display data can betransmitted to the display member in the wireless manner, and also, thefollowing problems which are conspicuously revealed in connection withenlarging of the display body can be eliminated. That is, caused by thedata transmission in the wire manner, for instance, power consumption,restrictions of wiring positions, EMI controls, securing of reliability,and so on. In particular, even when such a transmitter capable ofradiating extremely strong electromagnetic waves is present within thesame system, a superior system can be supplied without being adverselyinfluenced by interference.

Embodiment 2

FIG. 9 is a diagram for exemplifying a major unit of a conceptional ideaas to an electronic appliance according to another embodiment of thepresent invention.

In FIG. 9, reference numeral 501 indicates an internal appliancecommunication-purpose transmission antenna which corresponds to thetransmission antenna 103 of FIG. 4. Also, reference numeral 502 shows aninternal appliance communication-purpose reception antenna whichcorresponds to the reception antenna 104 of FIG. 4. Since these antennas501 and 502 correspond to small antennas, reactance components ofradiation impedance are large and are expressed as “R₁+jX₁” and“R₂+jX₂”, respectively. Normally, in the small antennas, the reactancecomponents “X₁” and “X₂” are capacitive and own negative values. Thesereactance components X₁ and X₂ may be offset by additionally employinginductance elements 503 and 504, which have values that these reactancecomponents X₁ and X₂become zero in a use frequency. Normally, sincecircuit wiring lines and the like own stray inductances, these strayinductances may be contained in a portion of the inductance elements 503and 504.

The stray reactance components can be offset in the above-describedmanner which have lowered the efficiency of the conventional circuit, sothat the system having the higher efficiency and the superiorcharacteristic can be realized. Reference numeral 508 indicates an inputterminal for inputting a signal from a transmitter output circuit. Animpedance converting operation is carried out by a matching circuit 506so as to establish a matching condition in such a manner that anequivalent output impedance 507 of this matching circuit 506 becomes“R₁.” It should also be noted that both the matching circuit 506 and theinductance 503 are formed with the transmitter output circuit in anintegral form to be designed under the normal condition. The inductance503 may be designed by considering the stray reactance components suchas a wiring inductance. Reference numeral 505 indicates a current sourceas an equivalent drive source, as viewing the transmitter output fromthe antenna side. While a real part “R₁” of a radiation impedance of asmall antenna is a small value, the output impedance 507 can be hardlymade coincident with this real part “R₁.” However, this difficulty maygive a convenience. This reason is given as follows. If the real part X₁is completely matched with the output impedance 507, then the efficiencyof the transmitter becomes excessively high, and the radiationelectromagnetic field becomes excessively strong, so that theelectromagnetic waves are radiated outside the system as spuriousradiation. Since this circuit portion is brought into a mismatchingcondition, excessive radiation can be avoided.

Also, since the output impedance may effect Q of the antenna range to belowered, it is possible to avoid that the transmission frequency rangebecomes excessively narrow due to the compact size of the antenna. Also,to the reception antenna 502, an inductance 504 is additionally providedas a reactance element capable of offsetting the reactance component ofthis reception antenna. Reference numeral 510 shows a matching circuit,and an input impedance 509 thereof as viewed from the antenna side inthe use frequency is designed in such a manner that this input impedance509 becomes “R₂.” The matching circuit 510 is designed by considering astray reactance and a characteristic of an input filter. The outputsignal of the matching circuit 510 is transmitted to an internalappliance communication-purpose reception unit 511.

All of these circuit elements except for the antenna radiator may beintegrated on a semiconductor integrated circuit so as to be madecompact and in low cost. In this case, although the sufficientlysuperior characteristic could not be conventionally achieved since theinductance of the bonding wire causes the disturbance, in accordancewith this system of the present invention, such a stray inductancecomponent may be used as a portion capable of offsetting the radiationreactance component of the antenna, so that the adverse influence by thebonding wire can be removed, and the electronic appliance having thebetter characteristic can be made compact and in low cost. It shouldalso be noted that the S parameter characteristic shown in FIG. 6illustratively represents a case that the matching condition isestablished in the manner as explained in this embodiment 2.

Embodiment 3

FIG. 10 is a block diagram for showing an arrangement of an electronicapparatus according to a further embodiment of the present invention.Since circuit blocks having the same reference numerals as those of FIG.8 are the same as those of FIG. 8, explanations thereof are omitted.These circuit blocks may be integrated on a semiconductor integratedcircuit so as to be made compact and in low cost. In this case, aninternal appliance communication-purpose transmission/reception antennamay offset a reactance component and may be operated in a narrowfrequency band in accordance with the method as shown in FIG. 9. At thistime, an adverse influence caused by an inductance component of abonding wire which connects the integrated circuit with the antennacould be eliminated in accordance with the above-described method.However, these fluctuations may appear as fluctuations of frequencyselection characteristic between the transmission antenna and thereception antenna. It is a cumbersome work to control these fluctuationsin higher precision. This embodiment 3 exemplifies a measure for thiscumbersome work.

That is to say, an evaluating circuit 601 evaluates an output of thedemodulating circuit 416 of the internal appliance communication-purposereceiving circuit based upon, for instance, an error rate and a signalstrength. Then, this evaluating circuit 601 feeds back the evaluatedoutput to the carrier wave oscillator 409 of the internal appliancecommunication-purpose transmission circuit, and changes the oscillationfrequency thereof so as to select an optimum frequency with respect tothe internal appliance communication. Changing of the frequency may beeasily realized by changing a frequency dividing ratio of a frequencydividing circuit, or by utilizing such a technique of avoltage-controlled oscillator and a PLL. While the positionalrelationship between the transmission and the reception is fixed in theinternal appliance communication, since the strengths of the radiatedelectromagnetic waves are very weak and do not conflict with thefrequency allowable deviation rule of the radio wave control law, theinternal appliance communication may be freely changed. Alternatively,since the signals for the feedback purpose are present within the sameappliance for transmission/reception operations, these signals may betransmitted by way of wire signals. As a result, the signal path for thefeedback operation is not required to be operable in the wirelessmanner, and thus the circuit may be simplified.

In accordance with the present invention, the system having the highreliability can be realized in the easy manner or in the low cost, whilepermitting the deviation caused by the fluctuations based upon thewiring line and the semiconductor integrated circuit process.

INDUSTRIAL APPLICABILITY

The present invention is not limited only to the signal connectionsbetween the main body unit and the display unit within the portabletelephones, but may be applied to various sorts of systems that aplurality of wireless systems are mutually provided within the sameappliance, for example, a system in which a wireless LAN is built.Conversely, the present invention may be utilized in an appliance thatan internal appliance communication is mutually carried out with areceiver for receiving very low-leveled electromagnetic waves such as aportable TV and a GPS terminal equipped with a display member, wherebythe inventive idea may be utilized in order to eliminate the adverseinfluences given to the original appliance communications, which arecaused by the internal appliance communication.

1. An electronic apparatus comprising: a first transmission unit thatperforms a first communication by a first electromagnetic wave; a secondtransmission unit that performs a second communication by a secondelectromagnetic wave; a reception unit that receives said secondelectromagnetic wave from said second transmission unit; and an antennaincluding a radiator that defines a sphere, where the diameter of thesphere is smaller than 1/(2π) of a wavelength of said secondelectromagnetic wave.
 2. An electronic apparatus, as claimed in claim 1wherein said antenna further comprises a reactance element that cancelsa reactance component of said radiator.
 3. An electronic apparatus, asclaimed in claim 1 wherein: said first transmission unit, said secondtransmission unit, or either a partial circuit or all circuits of saidreception unit are constructed on a semiconductor integrated circuit;and either a portion or all of reactance components of the radiator arecanceled by both a reactance component of a wiring line on saidsemiconductor integrated circuit, and a reactance component of a wiringline between said semiconductor integrated circuit and the radiator. 4.An electronic apparatus as claimed in claim 1, wherein: said radiatorhas a line shape.
 5. An electronic apparatus as claimed in claim 1,wherein: said radiator comprises a printed pattern on a printed circuitboard.
 6. An electronic apparatus comprising: a first transmission unitthat performs a first communication by a first electromagnetic wave; asecond transmission unit that performs a second communication by asecond electromagnetic wave; a reception unit that receives said secondelectromagnetic wave; an antenna including a radiator that defines asphere, where the diameter of the sphere is smaller than 1/(2π) of awavelength of said second electromagnetic wave; an evaluation unit thatevaluates a reception condition of said reception unit; a control unitthat controls a frequency of said second electromagnetic wave; and afeedback unit that feeds back an evaluation result made by saidevaluation unit to said control unit.
 7. A wireless communicationterminal comprising: a first housing unit; a second housing unit; acoupling unit that couples said first housing unit to said secondhousing unit in such a manner that a positional relationship betweensaid first housing unit and said second housing unit is changeable; anexternal wireless communication-purpose antenna mounted on either saidfirst housing unit or said second housing unit; an external wirelesscommunication control unit mounted on said first housing unit, thatcontrols an external wireless communication performed via said externalwireless communication-purpose antenna; a display unit mounted on saidsecond housing unit; a first internal wireless communication controlunit mounted on said first housing unit, that controls an internalwireless communication executed between said first housing unit and saidsecond housing unit; a second internal wireless communication controlunit mounted on said second housing unit, that controls an internalwireless communication executed between said first housing unit and saidsecond housing unit; a first internal wireless communication-purposeantenna mounted on said first housing unit, that includes a radiatordefining a first sphere, where the diameter of the first sphere issmaller than 1/(2π) of a wavelength of an electromagnetic wave used insaid internal wireless communication; a second internal wirelesscommunication-purpose antenna mounted on said second housing unit, thatincludes a radiator defining a second sphere, where the diameter of thesecond sphere is smaller than 1/(2π) of the wavelength of theelectromagnetic wave used in said internal wireless communication; andan internal wireless timing control unit that controls transmissiontiming of the electromagnetic wave used in said internal wirelesscommunication based upon transmission timing of an electromagnetic wavetransmitted via said external wireless communication-purpose antenna.